We are required to use LNT in the United States and Canada. The attributable cancer risk for CT colonography is a rounding error, and considerably lower than t

We are required to use LNT in the United States and Canada. The attributable cancer risk for CT colonography is a rounding error, and considerably lower than the quoted perforation risk. That said as a radiologist I personally still opt for colonoscopy screening, it is however an option for patients.